You are here

Jupiter at Opposition II

StarDate:

September 21, 2010

The planet Jupiter is quite a show-off right now. It's in view all night, and it's brightest for the year, too. In fact, it's the third-brightest object in the entire night sky, so it's hard to miss. Tonight, look for it low in the east at nightfall, well to the lower left of the Moon, and climbing high across the sky later on.

Jupiter is quite the show-off through a telescope, too. Its atmosphere is topped by bands of clouds that stretch all the way around the planet. They're colored in shades of brown, tan, and white, making the planet look like a striped beach ball.

Earlier this year, though, one of the planet's dark stripes lost its color. Known as the South Equatorial Belt, it went from a caramel color to pale pinkish-white. And that's a lot of territory to repaint -- the belt is wider than Earth.

This same belt of clouds has disappeared before -- most recently in the 1990s. Scientists aren't quite sure what causes the periodic vanishing act. The belt may get covered by clouds made of crystals of frozen ammonia -- similar to high-altitude water-ice clouds here on Earth.

Eventually, the South Equatorial Belt will return to view. And even as they ponder why the belt lost its color, scientists can get back to wondering why it's colored brown in the first place -- just one more mystery about the dynamic atmosphere of this big, showy planet.

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.